Multiple chamber valve plural motors



Sept 20, 1950 F. C. HABERLAND ETAL 2,953,164

MULTIPLE CHAMBER VALVE PLURAL MOTORS Filed April 29, 1957 4 Sheets-Sheet 1 GEZ F. c. HABERLAND ErAL 2,953,164

MULTIPLE CHAMBER VALVE PLURAL MOTORS Filed April/29, 1957 Sept. 20, 1960 4 Sheets-Sheet 2 /7z vemforzs'.'

TT uw Sept. 20, 1960 F. C. HABERLAND ErAL- 2,953,164

MULTIPLE CHAMBER VALVE PLURAL MOTORS' y Filed April 29, 1957 4 Sheets-Sheet 3 Sept. 20, 1960 l FL c. HABERLAND ETAL 2,953,164

MULTIPLE CHAMBER VALVE PLURAL MOTORS Unite MULTIPLE CHAMBER VALVE .PLURAL MOTORS This invention relates, in general, to power lawn mowers and Vin particular to hydraulic drives for power lawn mowers.

.It is a general object of Athis invention 4to .provide a new and improved power lawn mower, particularly of the riding type, .and itis aparticular object of .this .inven- -tion to provide .a `new .and improved .hydraulic drive for such lawn mowers.

`Still another and .more .particular .object .of this invention is to provide anew and improved diierential control valve for a hydraulic system which provides the hydraulic drive for power lawn mowers.

,These general .and particular .objects are-accomplished by the provision of a hydraulic system in ya power .lawn mower which distributes, .through .a new and improved diierential control valve, .tluid vunder pressure from Aan engine driven hydraulic pump to a pair of hydraulic motors to drive a pair .of traction wheels. Through the operation of the diierential control valve, the operator of the power .lawn mower may choose between `one or two wheel drive, in .forward -or reverse directions, of movement; the power lawn mower being vfurther provided with dierential action when turning-and a means of restoring traction should one wheel start spinning.

This differential control valve comprises a spool .valve having 'fluid pressure passageways formed fof Va selected shape and size which cooperate with .the Vinlet and outlet ports of the valve ,housingto .distribute duid under pres sure from the hydraulic pump to the hydraulic motors which drive the wheels. The .sizeand shapeof .the `lluid pressure passageways are selected to provide variable oriiices by their cooperation with the outlet .por-ts so `that the flow to a selected wheel may be restricted according to the desired requirements of the wheel. This brief resume of this invention will .be more completely understood from vthe more .detailed description herein.

Accordingly, .it is a still more particular object of .this invention to provide in a power lawn mower `a new .and improved differential valve which permits the choice of one or two wheeldrive -in forward or .reverse directions, which provides differential .action when turning the power lawn mower, and which has a means of restoring traction should one wheel ,start spinning.

-Another goal of this invention is the provision of .a dilierential valve ,havingfluid pressure .areas of a'selected size and shape which cooperate with the inlet and outlet ports Vto Select the amount and direction of flow through theseports according to .the requirements of the hydraulic motors which drive the wheels of the power lawn mower.

VOther and Vmore particular objects and advantages of the present invention will be apparent from :the following rates Patent IO 2,953,164 Patented Sept. 20, 1960 invention;

,'Fig. V`3 is a -sectional view of the differential control valve taken along line 3-3 of Fig. 2 and looking in -the direction Vof the arrows;

fFig. 4 is across-sectional view of the .differential control valve Ytaken along Vline 4 4 :of Fig. 3 and flocking in the .direction of the arrows;

fFi'g.. 5 .is a cross-sectional .View Vof thediierential control valve ,taken along line 5 5 of. Fig. 3 and looking in the direction Vof .the arrows;

Fig. .6 is a cross-sectional view of the differential control valve taken along line 6-6 of Fig. 3 and looking -in the .direction fof the arrows;

Fig. .7 is a semi-schematic, partial plan view Yof the power lawn mower, showing to advantage the position .of the fluid .pressure areas of the differential control valve as Vthey cooperate Awith .the inlet .rand `outlet ports Vfor forward movement, ,two wheel drive, of the power lawn mower;

Fig. .8 isa semi-schematic, partial plan View of the power lawn mower showing to advantage the position of theiluid pressure .areas of the differential control valve as they cooperate with the inlet and outlet ports for reverse movement, two wheel drive, lof the power lawn mower; v

Fig. 9 is a Vsemi-schematic, partial lplan view of the powerlawn .mower showing -to advantage the position of the fluid pressure areas of the directional rcontrol valve as they cooperate with 'the inlet and outlet ports :forforward movement of -the power lawn mower with right wheel drive only;

.,Fig. .l0 is -a 'semi-schematic, partial plan view of lthe power lawn :mower showing to advantage :the position :of the `lluidpressure yareas of the directional control valve as they` cooperate with the inlet and out-let ports for forward movement of the power lawn mower with Vleft wheel drive only;

'.Fig. ll is a vsemi-schematic, partial plan lview of the power lawn mower showing to ladvantage .the position rort the iluid pressure :areas of the directional control valve as they lcooperate with the inlet and -outlet ports for forward right turn of the power lawn mower with diierential ilow to the `right wheel;

Fig. `l2 is a semi-schematic, partial .plan view of the power rlawnmower showing to advantage the position of the fluid pressure areas of the directional control valve as they cooperate with :the inlet and outlet ports `:tor forward leftgtum of the ,power lawn mower-with differential ow'to the left wheel;

Eig. 13 Vis a `semi-schematic, partial plan View of the power lawn ymower showing `to advantage the positionof the fluid V.pressure areas of the .direc-tional control valve as they cooperate with the inlet and outlet Vports VAfor reverse right Vturnof the power lawn 4mower with litten ential ow -to the right wheel;

Fig. I14 is a semi-schematic, Ypartial plan view of the power `'lawn mower Ashowing -to advantage the position of the uid pressure areas of the directional control valve as they cooperate with the inlet and outlet ports for reverse left of the power lawn mower with diierenp tial flow to the left wheel.

Referring now to the drawings and in particular, to Fig. l thereof, it can be seen that there is disclosed a partially schematic plan view of a three-wheel power lawn mower wherein the left and right wheels W-1 and W-2, respectively, are each suitably driven through gear Yreduction means GR-l and GR-Z, by hydraulic motors wheels support engine E, usually of the gasoline type,

which is drivingly coupled through its drive shaft to a hydraulic pump P. Pump P supplies a ow of Huid under pressure, from reservoir R andline 11 through line 12 to hydraulic motor M-3 and line 13 to directional control valve C. The hydraulic motorM-3 is drivingly connected through a gear reduction means GR-3 toV grasscutting blade means B in the usual manner. These blades B may -be of the rotary or reel type as desired even through only rotary type blades are shown in the drawings. By-pass line 14, connected at one end between the hydraulic pump P and the hydraulic motor M-,3 and at the other end between hydraulic motor M-3 and diierential control valve C, provides a by-pass of hydraulic motor M-3 independent of the selected condition of the olf-on valve V. If the valve V is open and permits ow the hydraulic motor M-3 to drive the blades B and, conversely, if the valve V does not permit full ow through the Iby-pass line 14 full orpartial uid pressure is directed into motor M-3 to drive the blades B.

The directional control valve C isV provided with an inlet 15 in iluid communication with inlet line 13 and a pair of forward outlet and return ports 16 and 17 and a pair of reverse outlet and return ports 18 and 20. Forward outlet and return port 16 is connected by line 21Y to left motor M-1, and left reverse outlet and return port 18 is connected to motor M-1 lby line 22. Similarly, for- Y ward outlet and return port 17 is connected by line 23 Y through the by-pass line 14 there is insucient power in Attaching mechanism 38 comprises a pin 40 axially disposed in counterbore 37 having an enlarged end 41, a helically coiled spring 42 axially encompassing't-he middle portion of pin 40, anda fork-like means 43. One prong 44 is formed at one end with an enlongated slot 45 and at the other end with an inwardly extending lip portion 46 with a hole 47. The pinV 40 is received in hole 47 and arranged so that lip portion 46 is inserted between the end 41 and the spring 42. The other prong 48 forming the other half of the fork-like means 43 is provided with an elongated slot 50 Iat one end and at the other end with an inwardly extending lip portion 51 which in turn has a hole 52 formed therein. This latter lip portion 51 and hole 52 cooperates with the other end of the pin and is located between lock washer 53 and spring 42. It is to be noted that the prong 48 is longer than the prong 44 so as to cooperate with opposite ends of the pin 40, and that slots and 50 at the opposite endY of the fork are displaced relative to each other. Thus, with the slots 45V and 50 each forming a lost motion connection with linkage means 54, it can .be seen that movement of the linkage means 54 by rotation of the steering mechanism S causes prongs43 and 48 to move relative to one lanother to compress the spring 42 to the right or to the left. This pin 40 is in turn iixedly attached to the spool 33 by pin V55so that rotation of the steering wheel will ultimately move the spool to the right or to the left as desired. o

The spool 33 is provided intermediate its endswith an irregularly shaped recess means or pressure area 56 formed in the outer surface thereof and located between four intercommunicative rectangularly shaped recess means or pressure areas 57, 58, 60 and 61 also formed in the outer surface thereof. The irregularly shaped recess means or areaV 56 comprises an elongated middle portion 62, the longest portion of which extends in the major axial direction of the spool. The enlarged middle portion 63 of this irregular recess means or area extends circumferentially substantially yaround Vthe spool and is to n'ght motor M-1 yand the rightreverse outlet and re- Y turn port 20 is connected to motor M-2 by line 24.

Thus, it can be seen that the ow of fluid under pressure Y from the hydraulic pump P through inlet port 15 may be directed by the directional control valve through ports 16, 17, 18 and 20 as will be explained in detail hereinafter. Y

The directional control valve C is further provided with ports 25 and 26 which are interconnected byline 27 and by line 28 to the reservoir R to permit the return ofuid to the reservoir R. It is to be noted yalso that the hydraulic motor M-3 is connected by line30 to the return line 28 to permit the ow of uid from the hydraulic motor M-3 to return to the reservoir R.V o

Turning now to Fig. 2 it can be seen in this enlarged cross-sectional view that the directional control valve C comprises a housing 31 withV a cylindrical bore 32 in of a width greater than the width of the elongated portion 62. The irregular shaped lands 64, 65 on the valve which deiine thefour rectangular'areas'and the irregularly shaped middle area 56 serve to separate the various areas from each other. Itis important to note that the size or dimension of the irregular area 56 and particularly the elongated area 62 as well-as the -axial dimension of the rectangular areas 57, 58, `60 and V,61 are so constructed and arranged to cooperate with the inlet 15 and the outlets l16, 17, 18 and 20 as well as the return pressure ports 25 and 26 Yto provide a variable orifice with the respective outlets and return ports the reason for which Y WillV be described in detail.

which is received a cylindrical valve member or spool 33 suitably tted therein to permit axial movement to the right or to the left (as shown in this ligure) and rotatable movement about itsmajor eaxis. Suitable sealing means such as 34, 35 may be provided as desired at or near as screw means 72.

Communication between the various ports is accomplished by axial movement caused by the movement of the Vlinkage means 43 and 54 hereinbefore described and by rotational movement of the spool by control lever L xedly attached to the spool 33. Control lever L comprises a rod means 66 having a handle 67 formed at one end. The other end extends through a rectangularly formed slot 68 in the housing 31 so as to permit axial, forward and backward lmovementV of the rod. In this embodiment the lever L is affixed to the spool valve proper 33 by insertion of therend of rod 66 YOPPOSite handle 67 into a radially extending slot 70 formed in the right hand side of the spool andby retaining the rod in this slot by means of a U-,shaped bracket 7,1 apertured at each end to receive'the rod.Y The U-shaped means is itself affixed to the spool by any convenient means `Vsuch VThus with axial movement of the` spool to the right or to the left being accomplished by the rotational Ymovement of the steering wheel, Yor by hand under certain conditions, and with forward and backward movement ofthe handle67 causing rotational movement of the spool Vthe operator of the power lawn mower can completely control and direct the mower as will be explained,

in detail, hereinafter.

Turning now 4again to Fig. l, it is to be noted .thatlever L is in its center position. This position causes the flow `of fluidfpressure Yfrom the pump P to ow through line .13, inlet 15 and back through return lines 27 and 28 from return ports 25 and -26 hby reason of the fact that the irregular area 56 with its elongated portion 62 isin communication with the .inlet and pressure return ports 25 and .26. This is .the neutral .positionof the power lawn mower.

If the operator decides to travel straight forward with two wheel drive, he merely has to push the lever L forward, i.e., in the direction of wheel W-3, as shown in Fig. 7, so that the pressure from line -13 and inlet port 15 is directed to the two forward outlet and return ports 16 and 17 now in communication with the inlet 15 by reason of the change of position of the irregularly shaped area 56. Fluid under pressure is then directed to lines 21 and 23, respectively, and return pressure from lines 22 and 24, communicated to return lines 27 and 28 by reason of the communication between ports 18, 25 and 20, 26, which communication is accomplished by positioning the rectangular pressure areas 60 and 61 on the valve member or spool 33.

In a similar manner two wheel drive reverse travel with two wheel drive is easily accomplished by the operator positioning the lever L directly backward (or 0pposite from the position of lever L in Fig. 7) as shown in Fig. 8 so that the irregular area 56 communicates pressure from the inlet port 15 to the two reverse pressure and return ports 18 and 20. In this manner fluid under pressure is communicated to lines 22 and 24, respectively, and lines 21 and 23 become return lines 'm communication with the return lines 27 and 28 by the intercommunication of ports 16, 25 and 17, 26 accomplished through the rectangular areas 57 and 58 of the spool valve proper.

In either of these positions of two wheel drive direct forward or reverse travel, obviously, speed control can be accomplished by intermediate positioning of lever L between fully forward or fully reverse, thus by-passing some of the iiow back to the reservoir R; the amount of low ybeing by-passed back to the reservoir RV is a function of the pressure since the by-pass ports are xed orifices. Speed control also .of course, is not a function of the valve position alone but also Will depend on the load at the wheels.

By moving the spool 33 by means of lever L to the `extreme right or to the extreme left as shown in Figs. 9 and l0, respectively, whether the control lever L is fully forward, fully in reverse or at any intermediate position, one wheel drive through either the left wheel W-l or the right wheel W-Z, forward or reverse direction, is accomplished. Speed control is also accomplished by partially by-passing some of the Huid under pressure back to the reservoir as explained in connection with Figs. 7 and 8.

Figs. 1l and l2 clearly illustrate the position of the spool valve as it is aifected by movement of the steering wheel S through linkage means 54 and 43 to accomplish forward right and left lturns of the power mower, respectively. It is important to note that either in this right or left turning position, the elongated portion 62 of the irregular pressure area 56 of the spool valve 33, as well as the extreme right or left of the rectangular areas 60 and 61, only partially uncover the ports 16, 18, 25 or 17, 26 and 20, as the case may be, for differential control of either the left or the right wheel, depending on the direction of turn. Obviously, the pressure areas in question cooperate with the respective ports to provide oriiices to accomplish this diiferential control and the amount of orifice opening will, of course, depend on the amount of turn in the steering Wheel S.

Also, .it is to -be noted that the one side of the areas functions to provide a variable oriiice, the Yother vside of the areas provides more flow to Ythe hydraulic motor. Also, any steering on the part of ,the operator will cause flow to be by-passed back to the reservoir. Figs. 13 and 14 show diierential reverse right and left turns of the power mower. VSince the function of the valve is exactly the sameI as explained in connection with Figs. 1l and l2 except that the :areas and the ports dividing the ow of uid in the `opposite direction to 'the hydraulic motors, no further description herein is deemed necessary.

Finally, as another accomplishment in this invention, should any one of the power wheels W-1 or W-2 start spinning causing loss of traction, traction can be restored by either turning the steering wheel to restrict the flow of iiuid to the spinning wheel until traction is restored or by moving the control handle against the spring 42, the choice of these two methods being up to the operator.

While the device has been described with reference to a particular direction, it is to be understood that this is merely to facilitate the description and is not to be considered a limitation.

While this invention has been described in connection with one embodiment thereof it is to be understood that this is by way of illustration and not by way of limitation and the scope of this invention is defined solely by the appended claims would should be construed as broadly as the prior art will permit.

We claim:

l. A differential control valve comprising: a housing having a cylindrical bore and having -an inlet port and a plurality of outlet ports provided therein, a valve member having an outer peripheral surface disposed in said cylindrical bore for axial and rotatable movement therein, said valve member having a rst recess means and a pair of rectangular recess means provided in said outer surface, said iirst recess means being provided with a portion elongated in the direction of the axis of said valve member and being provided with an enlarged middle portion, all of said recess means provided in said valve member being cooperable with said outlet ports to provide ow through some of the outlet ports while preventing flow through others under certain selected conditions land to restrict the amount of ow through some of said outlet ports while permitting flow through the others under certain other selected conditions.

2. A diierential control valve comprising: a housing having a cylindrical bore and having an inlet port and a plurality of outlet ports provided therein, a valve member having an outer peripheral surface disposed in said cylindrical bore for axial and rotatable movement therein, said valve member having an irregularly shaped rst recess means and a pair of rectangular recess means provided in said outer surface, said iirst recess means being provided with a portion elongated in the direction of the axis of said valve member and being provided with an enlarged middle portion, all of said recess means provided in said valve member being cooperable with said outlet ports to provide iiow through some of said outlet ports while preventing flow through others under certain selected conditions and to restrict the amount of ow through some of said outlet ports while permitting flow through the others under certain other selected conditions.

3. A differential control valve comprising: a housing having a cylindrical bore and having an inlet port and a plurality of outlet ports provided therein, a valve member having an outer peripheral surface disposed in said cylindrical bore for axial and rotatable movement therein, said valve member having a rst recess means and a pair of rectangular recess means provided in said outer surface, said iirst recess means being provided with a portion elongated in the direction of the axis of said valve member and being provided with `an enlarged middle portion being arranged to cooperate with said inlet port, al1 of said recess means provided in said valve memberbeing cooperable with said outlet ports to provide 110W through some of said 'outlet ports while preventing flow through others under certain selected conditions and to restrict the amount of flow through Vsome of said outletports While permitting flow through the others under certain otherr selectedconditions.V

References Cited in the le of'this patent UNITED STATES PATENTS 8 Y Madsen Mail 28, 1940 Brathwaite Apry, 1951 Rose r AJuly` 1,j 1952 Lindquist Sept. v9, 1952 lVahs Mar. 15,1955 Nubling Mar. 20, 1956 King Oct; 9, 1956 Vogelaar Ost. 16, 1956 Boyer Oct. 16, 1956 

